Sensitized paper for photographic printing.



@ UNITED STATES PATENT OFFICE,-

REDEIELD B. WEST, OF GUILFORD, CONNECTICUT SE NSITIZED'PAPER 'FORPHOTOGRAPHIC PRINTING.,

SPECIFICATION forming part of Letters Patent No. 674,227, dated May 14.,1901.

' Application filed February 26, 1901. Serial No. 48,955. (Nospecimens.)

To all whom it may concern Be it known that I, REDFIELD B. WEST, ofGuilford, in the county of New Havenand State of Connecticut, haveinvented a new Sensitized Paper for Photographic Printing; and I dohereby declare the following to be a full, clear, and exactdescription'of the same. This invention relates to an improvement insensitized paper forphotographic printing, and particularly to paper. inwhich the print is fixed after exposure by a'bath of water, the objectbeing to produce prints closely resembling in colorthe prints producedby the use of platinum; and it consists in paper sensitized with acompound, as hereinafter described, and particularly recited in theclaim.

The sensitizing compound consists of 1ner curous nitrate,eight parts;ferriclactate,eight parts; water, one hundred parts. These parts areunited, and paper of suitable quality is coated with the compound, andWhen thus coated and placed under a negative or drawing to be copied andexposed for a sufficient time to light shows a print of a light-browncolor, The print thus made is immersed in water, in which it should beallowed to remain until all of the salts which have not been acted uponby the light are removed from the paper, which is then removed from thebath and allowed to dry. As before stated, these prints closely resemblein color and appearance prints produced with the use of platinum.

The advantages possessed by making prints with my improved paper overthat in which platinum is employed are a great reduction 5 in the costof preparation and the avoidance of all chemical solutions in bathscommonly i used for developing, fixing, and clearing such prints. Theferric lactate is particularly adapted, for use with mercurous nitratein this composition for the reason that no precipitation occurs when thesolution of the two salts is made.

Other ferric salts, as a rule,-

give insoluble precipitates with solutions of I mercurous salts. I

The proportions given in the formula may be varied to a certain extent.without materially afiecting the result, I do not, therefore, wish to beunderstood as limiting the invention'to the exact proportions named;but, Having fully described my invention, what I'claimas new, and desireto secure by Letters Patent, is t l g A sensitized paper forphotographic printing, consisting of a paper coated with a solution ofmercurous nitrate, ferric lactate and water, inthe proportionssubstantially as described.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

REDFIELD B. WEST.

:Witnesses:

FRED. C. EARLE, LILLIAN D. KELSEY.

